They don't mention it here, but I think they might on a different post? Rivers are going to show up more in a monospace font (which your link points out), so that would make sense. With modern fonts it makes sense to be putting the spaces in after a sentence stops for readability though. Microsoft word allows for manipulating spacing anywhere there are still rivers.
The main use of computers in school should be teaching typing, word processing (and it probably should be with Word), number crunching and mathematics, and perhaps a little bit of graphics processing.
I agree that Excel should be taught, but also something like Mathematica (or some other CAS, rather than forcing TI calculators on kids). Python, perhaps through Jupyter Notebooks, would also probably be good too.
Honestly, for adults too, pen and paper is often a better solution. Word processing and number crunching are the main use cases for a computer and I think kids should learn these things with a computer, but it would be so much better if they had direct instruction in a computer lab rather than giving them all a distracting laptop/chromebook.
